An important factor in developing skill in many sports is the ability of the player to strike an object with an implement swung at high speed. For example, the power with which a tennis ball is hit is proportional to the velocity of the racquet head at the point of impact. Similarly, the distance which a golf ball will travel after having been struck with a golf club is dependent in large part upon the club head velocity at the point of impact with the golf ball. Also, the power which a baseball batter generates in striking a pitched ball is proportional to the velocity of the barrel of the bat when the ball is struck. Accordingly, it is advantageous for participants in these and similar sports to be able to generate maximum speed of the racquet head, club face, or bat barrel.
The path followed by the racquet head, club face, or bat barrel when swung by a player is essentially arcuate. The characteristic of an implement swung in an arcuate path which imparts kinetic energy to a struck object is the linear or tangential velocity component of the implement at the point of impact with the object. This tangential velocity component of the swung implement will be referred to hereinafter as the "swing velocity". To train players in these various sports to generate maximum swing velocity, it would be helpful to have some objective indicia of the swing velocity so that the effect of changes or refinements in swing technique on the swing velocity can be measured.